German Patent Application DE 101 00 247 describes a microscope that is equipped with two objectives so that a specimen carrier can be examined from both sides, thus achieving an improvement in resolution. For that purpose, the specimen carrier comprises two coverslips that define a cavity for the sample to be examined. One of the coverslips carries an optically detectable layer which thus facilitates focusing. The disadvantage of this sample carrier is that the optically detectable layer also extends over the sample to be examined. This undoubtedly influences the detectability of the sample.
Specimen coverslips in which one half of the sample space is mirror coated in half-moon fashion have been used hitherto. Another method is to introduce small mirror-coated flakes into the sample in distributed fashion.
A disadvantage in present confocal microscopy is the removal of alignment means from the focal plane, which creates difficulty or uncertainty when subsequently viewing samples with the microscope that has just been prealigned.
The optical configuration of a microscope must be modified specifically by the removal of the alignment means.
The half-mirror-coated coverslips have the disadvantage that the user often has difficulty finding the mirror-coated surface. In addition, the sample region is so large that the sample often cannot be effectively located. The method with the mirror-coated flakes is not suitable, since the flakes are difficult to find and also subject to damage.